Diagnosis and etiology
The patient was a 30 years-old woman with a chief complaint of
protrusive lips, proclined
maxillary incisors, anterior spacing, and recession on mandibular
incisors. Extra-orally, she had a convex profile with an acute
nasolabial angle, a strain on the circumoral muscles while closing her
mouth, and a proclination of the upper incisors was observed when the
patient smiled. No symptom of temporomandibular disorders was detected
(Figure 1a, 1b).
Intraorally, the patient had a Class I molar and canine relation on the
right side, a Class I molar and a Class II canine relationship on the
left side, and peg-shaped lateral incisors. The patient only had 3 lower
incisors present, diastemas in the maxillary and mandibular anterior
teeth because of the tongue’s position, and recession on the lower
incisors. The upper and lower arch forms were typically developed, and a
flat Curve of Spee was observed. The patient demonstrated Bolton’s tooth
size discrepancies because of the 3 lower incisors. The upper midline
coincided with the facial midline. The lateral cephalometric analysis
showed a skeletal Class I jaw relationship with proclined upper and
lower incisors. Both the upper and lower lips were in front of the
E-line (Figure 1c).